KR100223383B1 - Mixing and chemical feeding methods and equipments for waste water treatment - Google Patents

Abstract

The present invention relates to a water treatment for chemically removing contaminants in water or wastewater, wherein a nozzle is installed in the reaction tank, and the nozzle is connected to a discharge port of a raw water inflow pump or a circulation pump, and the raw water inflow pump or circulation pump Ejector is installed in the discharge port and the chemical injection pipe is connected to the ejector or the chemical injection pipe is connected to the suction port of the circulating pump. Since the injection pump can be omitted, it is possible to reduce the facility cost and maintenance cost of the water and wastewater treatment apparatus.

Description

Mixing and Chemical Feeding Methods and Equipments for Waste Water Treatment

The present invention relates to a water treatment for chemically removing contaminants in water or waste water. In particular, the present invention relates to agitating a reaction tank for a chemical reaction using a raw water inflow pump or a circulation pump and an ejector without using a separate stirring device or a chemical injection pump. It relates to a stirring and drug injection device and a method for injecting or injecting a drug.

In general, methods for removing contaminants from raw water such as water or wastewater are classified into physical, chemical, and biological methods, and various combinations of the above methods are used depending on the characteristics of the contaminants. Among them, the chemical treatment method is composed of unit processes such as oxidation, reduction, neutralization, adsorption, and coagulation. When the treatment method is performed, chemicals required for reaction are injected into a reactor into which raw water is introduced. The residence time and mixing strength of

The conventional water treatment process is shown in Figure 4, the method for treating water and wastewater consists of the step of precipitation after the adsorption and flocculation reaction in the physicochemical method.

In such a water treatment process, depending on the reaction step, the raw water of the adsorption reaction tank, the flocculation reaction tank and the floc forming reaction tank, or the water body after the previous stage of reaction, the chemicals such as the adsorbent, the flocculant, the alkaline agent and the flocculent aid are different. A chemical injection pump 101 for injection should be installed, and a propeller or paddle type stirrer 102 should be separately installed in order to obtain a predetermined mixing strength in each reactor.

Therefore, it is disadvantageous in terms of the installation and maintenance of the device, in particular, the drug injection pump 101 is expensive and the agitator 102 is also expensive because it is a relatively expensive equipment used a reduction gear was expensive because of the high facility costs.

Accordingly, the present invention has been made in order to solve the above problems, and provides a stirring and chemical injection device that can reduce the facility cost and maintenance costs by replacing the conventional water treatment agitator and chemical injection pump. There is a purpose.

In addition, another object of the present invention is to provide a stirring and chemical injection method as described above.

In the water treatment apparatus according to the present invention for achieving the above object, a nozzle is installed in the reaction tank, the nozzle is connected to the discharge port of the raw water inlet pump or the circulation pump, the ejector of the raw water inlet pump or the circulation pump Is installed, the ejector is composed of a chemical injection pipe is connected or the chemical injection pipe is connected to the suction port of the circulation pump.

In addition, the chemical injection pipe is provided with an automatic valve for injecting an oxidizing agent and a reducing agent or an acid and an alkali or powdered activated carbon, and the automatic valve includes an ORP controller or a hydrogen ion concentration controller (pH controller). ) Or suspended solids controller (MLSS Controller) is installed to operate in conjunction with, the detection unit of the controller is a structure that is installed in the reaction vessel in which the drugs are injected.

In addition, the stirring and chemical injection method for achieving the above object of the present invention, the water flow is injected into the water body in the reaction tank through the nozzle installed in the reaction tank by the operation of the raw water inlet pump or the circulation pump energy of the injection water flow The water body inside the reactor is agitated, and a negative pressure is formed inside the ejector installed in the discharge tube of the pump by the operation of the pumps, and by this negative pressure, the chemical is sucked into the ejector through the chemical injection pipe, thereby discharging the pump. While mixing with water is introduced into the reactor with the water flow through the nozzle to be mixed and stirred. At this time, it is possible to finely adjust the mixing strength of the reaction tank by adjusting the injection flow rate of the nozzle by adjusting the valve installed in the pump.

And, except when two or more kinds of chemicals are used in the same reactor, such as flocculant and alkali or oxidizing agent and acid, the chemicals can be dispensed by the suction lift when the pump is operated by connecting the chemical injection pipe to the suction port of the circulation pump. The method of injection is implemented.

In addition, the automatic valve installed in the chemical injection pipe such as the oxidizing agent and the reducing agent or the acid and the alkali or powder activated carbon is opened and closed in conjunction with various controllers in which the detector is installed in the reactor, thereby automatically adjusting the chemical injection amount required for the reaction.

1 is a schematic view of the water treatment process consisting of the stirring and chemical injection device according to the present invention,

2 is an example of a stirring and chemical injection device according to the invention,

3 is a schematic view of a drug injection tube according to the present invention,

Figure 4 is a flow chart of a conventional water treatment agitation and chemical injection device.

* Explanation of symbols for main parts of the drawings

1: 1st reactor 2: 2nd reactor

3: 3rd reactor 3a: reactor

4: settling tank 8, 8a, 8b: ejector

9, 9a, 9b: nozzle 10: raw water pump

11, 11a: circulation pump 12: chemical injection pipe

13, 13a: regulating valve 14: automatic valve

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

1 is a schematic configuration diagram of a device implementing the stirring and chemical injection method for water treatment according to the present invention, the reaction tank in the chemical water treatment unit process for water or waste water treatment, the raw water inlet pump or circulation pump and ejector It is structure to include.

That is, the raw water is introduced into the sump and collected, and then the raw water inflow pump 10 is introduced into the primary reaction tank 1 and the reaction proceeds. After the reaction is completed in the primary reaction tank 1, the secondary reaction tank ( 2), the third step reaction tank (3) or sedimentation tank (4), etc. are carried out step by step. At this time, the adsorption reaction proceeds by injecting an adsorbent such as powder activated carbon into the primary reaction tank (1), and in the secondary reaction tank (2), a flocculant and an alkali agent are injected to cause an agglomeration reaction, and again in the tertiary reaction tank (3) In (4), flocculation reaction is performed to increase the size of the aggregated particles by injecting a flocculent aid so that precipitation is well achieved.

However, the scope of the present invention is not limited to the adsorption agglomeration reaction and can be widely applied to chemical wastewater treatment by oxidation, reduction, neutralization or various combinations thereof.

In the water treatment apparatus according to the present invention, the primary reactor 1 is provided with a nozzle 9 in water and the discharge port of the raw water inlet pump 10 and the nozzle 9 are connected by a pipe. In addition, an ejector 8 for chemical injection is installed in the discharge tube 15 between the discharge port of the pump 10 and the nozzle 9, and the chemical injection tube 12 is connected to the ejector 8. . A chemical tank (not shown in the drawing) is positioned at the tip of the chemical injection tube 12, and the chemical tank is filled with chemicals required by an adsorbent or a process such as acid or alkali, powder activated carbon suspended in a liquid phase.

On the other hand, the secondary reaction tank (2) is provided with a circulation pump 11 for pumping the water body in the secondary reaction tank (2) and flowing it back into the same secondary reaction tank (2), and the nozzle in the water inside the reaction tank (2) (9a) is provided in two series. The ejector 8 is installed in each of the two lines of the nozzle 9a, and the chemical injection pipe 12 is connected to the ejector 8a, and the nozzles 9a and the ejector 8a of the two lines are It is connected to the discharge pipe 15a of the circulation pump 11. Each chemical injection tube 12a is connected to a chemical tank filled with a flocculant and an alkaline agent, respectively.

The nozzle 9b is also installed inside the tertiary reactor 3 and the ejector 8 to which the chemical injection pipe 12 is connected is installed in the pipe in which the nozzle 9b is installed, and again the discharge pipe 15b of the circulation pump 11a. ).

Looking at the stirring and chemical injection method of the water treatment stirring and chemical injection device according to the present invention configured as described above are as follows.

In the case of the primary reactor 1, when the raw water inflow pump 10 is operated, a negative pressure is formed in the ejector 8, and the chemical is injected into the ejector 8 through the chemical injection pipe 12 by the suction force by the negative pressure. As it is sucked into and mixed with the raw water is injected into the reaction tank 1 through the nozzle (9) installed in the reaction tank (1).

At this time, the water body inside the reaction tank 1 is agitated by the energy of the water flow injected through the nozzle 9 and reacts with the chemical injected through the ejector 8. Therefore, even without a separate stirrer and a chemical injection pump, by the ejector 8 and the nozzle 9, the stirring and chemical injection can be effectively performed in the first reaction tank 1.

In the case of the secondary reaction tank (2), the operation process of the device for injecting stirring and chemicals is the same as in the first reaction tank (1). However, in order to solve the problem that the raw water inflow pump 10 cannot be used since the second and subsequent reaction tanks cannot directly flow into the raw water rule secondary reaction tank 2 that has not undergone the first reaction, instead of the raw water inflow pump 10. The circulation pump 11 which circulates the water body inside the reactor 2 is used.

The nozzle 9a, the ejector 8a, and the chemical injection pipe 12a are series-integrated and the chemicals are separated and injected to coagulate when the coagulant and the alkali agent for the coagulation reaction are mixed in the conduit without mixing in the reactor 2. This is because the efficiency is lowered to solve this problem. As in the secondary reaction tank (2), the type of injecting different types of chemicals is not limited to agglomeration reaction but also used for injecting oxidizing agent and acid for oxidation reaction or reducing and alkaline agent for reducing reaction. Will be.

In the third reaction tank (3), the stirring and chemicals are injected by a separate circulation pump (11a) for circulating the water body therein, which means that the raw water without passing through the first reaction tank (1) or the water without passing through the secondary reaction is Inflow to the third reaction tank (3) is to solve the problem that the treatment efficiency is lowered. The reason why the nozzle 9b and the ejector 8b are used in one series is to inject only one kind of chemicals, and the method is the same as in the reactors 1 and 2 of the previous stage.

2 is an example of a drug injection device according to the present invention.

The ejection port of the circulation pump 11b does not have an ejector, and instead has a structure in which the chemical injection pipe 12c is directly connected to the suction port of the circulation pump 11b.

That is, when the circulation pump 11b is operated, the medicine is injected through the chemical injection pipe 12c connected to the suction port by the pumping force of the circulation pump 11b. Therefore, no chemical injection pump is required and the ejector structure is omitted. In addition, there is an advantage that the drug is well dissolved and mixed in the waste water by the rotational force of the rotary wheel of the pump 11b.

3 is a block diagram of a drug injection pipe according to the present invention.

An automatic valve 14 is installed in the chemical injection pipe 12, and the automatic valve 14 is connected to an ORP controller, a pH controller, or a suspended solids controller (MLSS Controller). It is configured to open and close. Therefore, when injecting an oxidizing agent or a reducing agent, an acid or an alkali, or powdered activated carbon, it is possible to automatically adjust the chemical injection amount by the respective controller. However, since the operation of the automatic valve 14 is not a proportional control and opens and closes, the opening and closing operation frequency of the valve 14 is excessively excessive in a short time, and thus the controller and the automatic valve are overwhelmed. By-pass) pipes are provided in each of the manual control valves (13, 13a) and by adjusting them so that the automatic valve 14 is not frequently opened and closed to reduce the number of operations.

On the other hand, according to the stirring and chemical injection method and apparatus of the present invention described above, the sewage was treated in the following specific examples, the results of the specific implementation is as follows. However, the following examples illustrate the invention but do not limit it.

EXAMPLE

When the wastewater with a flow rate of 1000 m3 / day is rapidly stirred at a velocity gradient of 400 sec ⁻¹ in a primary reaction tank 1 having a residence time (HRT) of 5 minutes, spraying from a nozzle installed in the reaction tank 1 Speed and the required head lift in the raw water inlet pump 10 is as follows.

The capacity (V) of the reactor 1 is 3.5 m ³ and the power (P = μVG ² ) required for stirring takes about 728 watts when the viscosity of the water body is 1.3 × 10 ⁻³ kg · s / m ² . Assuming that the waste water density (ρ) is 1000 kg / m 3, the required spraying speed (υ =) at the nozzle 9 is 11.2 m / sec, and thus the required head (H =) at the nozzle is 6.4 m. Therefore, the head is added to the raw water inlet pump 10 for stirring is 7.7m by applying a margin of 20% considering the head loss in the piping. At this time, when the diameter of the nozzle 9 is 20 mm, three nozzles are required.

Therefore, the facility lift of the raw water inlet pump 10 is increased by 7.7 m and three nozzles having a diameter of 20 mm are installed in the reaction tank 1, thereby enabling rapid stirring for economic reaction without installing a stirrer.

As described above, by using the stirring and chemical injection method for the water and wastewater treatment and the apparatus according to the present invention, it is possible to omit a separate stirrer and a chemical injection pump in the water treatment process, the facility cost of the water and wastewater treatment plant And maintenance costs can be reduced.

Claims (8)

A stirring and chemical injection device for water treatment in which a nozzle (9) connected to the discharge pipe (15) of the raw water inflow pump (10) is installed in the reaction tank (1) so that raw water is injected into the reaction tank (1) through the nozzle. Nozzles 9a and 9b are provided in the reaction tanks 2 and 3, and a circulation pump 11 for pumping water bodies inside the reaction tanks 2 and 3 and circulating them back to the same reaction tanks 2 and 3 is installed. The nozzles 9a and 9b are connected to the discharge pipes 15a and 15b of the circulation pump 11 so that the water bodies in the reaction tanks 2 and 3 are again inside the reactors 2 and 3 through the nozzles 9a and 9b. Stirring and chemical injection device for water treatment, characterized in that the injection cycle. 3. The stirring and chemical injection device of claim 2, wherein an ejector 8a is installed in the discharge pipe of the circulation pump 11, and a chemical injection pipe 12a is connected to the ejector 8a. . 3. The stirring and chemical injection device for water treatment according to claim 2, wherein the chemical injection pipe (12a) is connected to the suction pipe of the circulation pump (11a). The method of claim 3, wherein two or more series of nozzles (9) are installed in the reaction tank (2), and the ejector (8) is installed in each of the inflow pipes of the nozzle (9), and then connected to the circulation pump (11). Stirring and chemical injection device for water treatment, characterized in that the injection of the drug. The adjustment valves 13 and 13a are provided in the chemical injection pipes 12a and 12b, and the adjustment valves 13a are parallel to the control valves 13 and 13a. And agitating and chemical injection device for water treatment, characterized in that the bypass pipe is provided with an automatic valve (14). 7. The automatic valve (4) according to claim 6, wherein the automatic valve (4) is to be opened and closed in conjunction with a pH controller, an ORP controller, or a suspended solids controller (MLSS Controller) in which a sensor is installed in the reactor. The valve (13, 13a) can be adjusted manually to minimize the number of opening and closing operations of the automatic valve 14, the water treatment stirring and chemical injection device. 2. The stirring and chemical injection device of claim 1, wherein an ejector (8) and a chemical injection tube (12) for chemical injection are installed in the discharge pipe (15).

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